The wrench locking device of this invention is classified in Classes 81/53, 81/128 and the like.
Seaver, in U.S. Pat. No. 2,483,713 issued Oct. 4, 1949, discloses a pipe wrench with a link mounted lower jaw which cooperates with an adjustable and swingable upper jaw, so that the wrench will have a strong self-tightening grip. In U.S. Pat. No. 1,921,281 issued Aug. 8, 1933, Carlson discloses an adjustable locking tubing tong having a U-shaped frame adapted to fit around a pipe. There are pipe engaging jaws at one side of the U-shaped frame and an engager slidably mounted on the other side of the frame. A pivoted handle on the frame is so equipped that movement of the handle in forward direction will produce an inward movement of the engager against the pipe held in the frame. Baash et al discloses in U.S. Pat. No. 1,845,389 issued on Feb. 16, 1932 a tong for securing round pipes by operating the actuating line carried by the handle and securing the gripping jaws around a pipe. Pietsch discloses a wrench in U.S. Pat. No. 1,569,673 of Jan. 12, 1926, wherein a movable jaw can be quickly moved to any position with respect to a fixed jaw, and then locked in position.